Isolated Galaxies versus Interacting Pairs with MaNGA

TL;DR

This study compares the star formation histories of isolated spiral galaxies and merging galaxies using MaNGA data, revealing inside-out growth in isolated galaxies and interaction-induced central star formation in mergers.

Contribution

It provides the first spectral analysis of radial star formation history distributions in both isolated and merging galaxies observed with MaNGA.

Findings

Isolated galaxy's center has older stars (~2 Gyr) than outskirts (~7 Gyr).

Mergers show older stars in the center and enhanced star formation due to interactions.

Inside-out galaxy growth is supported by the observed stellar population distributions.

Abstract

We present preliminary results of the spectral analysis on the radial distributions of the star formation history in both, a galaxy merger and a spiral isolated galaxy observed with MaNGA. We find that the central part of the isolated galaxy is composed by older stellar population ($\sim$2 Gyr) than in the outskirts ($\sim$7 Gyr). Also, the time-scale is gradually larger from 1 Gyr in the inner part to 3 Gyr in the outer regions of the galaxy. In the case of the merger, the stellar population in the central region is older than in the tails, presenting a longer time-scale in comparison to central part in the isolated galaxy. Our results are in agreement with a scenario where spiral galaxies are built from inside-out. In the case of the merger, we find evidence that interactions enhance star formation in the central part of the galaxy.